THE WORKING-PLAN 99 
somewhat broken, with low swampy tracts near the 
streams and lakes. Numerous knolls and ridges, from 
a few yards to over three hundred feet in height, rise 
from the lower ground. In general the ridges or series 
of ridges run northeast and southwest. Low rounded 
knolls rising above swampy ground are very frequent. 
More level areas, or flats, are of considerable extent ; 
some of them low and rolling and covered with glacial 
boulders. There are numbers of broad flat ridges. The 
higher hills are for the most part conical, with small 
tops, or consist of long narrow ridges. A glance at 
the map will indicate that the southerly slopes are apt 
to be rocky, abrupt, or often even precipitous. The 
northerly slopes are more gradual. The country shows 
in many ways the effect of the ice with which it was 
once covered. The soil is a glacial drift, and the man- 
ner in which the rocks have been smoothed off and the 
rounded boulders deposited on the flats and on the south 
slopes affords similar evidence. The shape of the 
ridges is due to glaciation. 
Granite, varying much in color and texture, is the 
principal rock. 
The typical soil of the Park is glacial gravel or sand, 
replaced by loam in richer situations. On steep slopes 
it is thin, and what there is usually collects in hollows, 
on benches, on the uphill side of rocks and trees, or in 
rocky crevices. On moderate slopes and high flats the 
soil is deep, fresh, and porous ; on low flats moist and 
often deep; on less level flats thin on account of the 
boulders ; and in swamps a deep muck. 
